V1 neurons exhibit selective responses to low-level visual features, such as color, orientation, and motion ( Livingstone and Hubel, 1984 Niell and Stryker, 2008). The primary visual cortex (V1) mediates visual perception of the external world ( Leopold, 2012 Glickfeld et al., 2013 Petruno et al., 2013). These plastic modifications rely largely on N-methyl- D-aspartate receptor (NMDAR) activity ( Kleinschmidt et al., 1987 Malenka and Bear, 2004 Michmizos et al., 2011). Although it generally takes several days to weeks for detectable changes to occur ( Frenkel et al., 2006 Cooke and Bear, 2010 Kreile et al., 2011), a few rapid forms of plasticity induction, such as exposure to a photic tetanus, have also been reported ( Teyler et al., 2005 Clapp et al., 2006). Increasingly, however, recent studies have devised experimental protocols to induce plasticity in adult visual systems via externally presented, noninvasive visual stimuli. To induce in vivo plasticity in adult cortical networks, researchers often use invasive approaches, including electrical and iontophoretic stimulation ( Frégnac et al., 1992 Schuett et al., 2001). We propose that flashing light stimuli can be used as an experimental tool to investigate the visual function and plasticity of neuronal representations and perception after a critical period of neocortical plasticity.Ĭortical response properties undergo prolonged plastic changes throughout life, but plasticity capacity is known to decline with age ( Frégnac et al., 1992 Frenkel et al., 2006 Levelt and Hübener, 2012). The neurophysiological and behavioral plasticity both persisted for at least several hours and required N-methyl- d-aspartate receptor activation in the visual cortex. The flash stimulus–induced underrepresentation of the grating motion was specific to the direction of the conditioned stimuli and was associated with a decrease in the animal’s ability to detect the motion of the drifting gratings. When the mice were repetitively presented with drifting grating stimuli (conditioned stimuli) during the flash stimulus–evoked delayed response period, the V1 neurons exhibited a long-lasting decrease in responsiveness to the conditioned stimuli. Our previous studies have shown that, in the primary visual cortex (V1) of mice, a flashing light stimulus evokes a long-delayed response that persists for seconds. Here, we describe a new method for the noninvasive induction of long-term plasticity in the mature brain: simple transient visual stimuli (i.e., flashing lights) can be used to induce prolonged modifications in visual cortical processing and visually driven behaviors. This reorganization occurs primarily through activity-dependent plasticity and has been well documented in animals during early developmental stages. The primary sensory neocortex generates an internal representation of the environment, and its circuit reorganization is thought to lead to a modification of sensory perception.

Flashing lights video effect